What happened
During a demonstration flight at High Prairie Airport, Alberta, a Piper PA-12 experienced a fatal loss of control shortly after takeoff. The owner of the aircraft was performing a flight for a prospective buyer, who was seated in the rear of the plane. After a normal takeoff roll on runway 07, the aircraft climbed steeply to approximately 150 feet above the ground. Following this steep ascent, the aircraft pitched nose-down and entered a one-quarter turn spin, plunging vertically into the ground. An intense fire broke out upon impact, and both the pilot and the passenger sustained fatal injuries.
The investigation
Investigators examined the wreckage and the aircraft's maintenance history. The aircraft had been modified with a more powerful 150-horsepower Lycoming engine and a "Borer" propeller. While the aircraft was at or near its maximum gross weight, the center of gravity was within limits. The investigation also looked into the aircraft's trim settings, noting that the horizontal stabilizer yoke was positioned near the bottom limit of travel, which creates a nose-up trim condition.
Furthermore, the investigation reviewed the pilot's recent flying experience and the aircraft's equipment. It was noted that the aircraft lacked a stall warning device and was being operated using unleaded automotive fuel without documented authorization. The investigation also found that the aircraft's seat belts used an obsolete design and the aircraft lacked shoulder harnesses.
Findings
- The aircraft stalled on departure for reasons unknown.
- The low altitude at which the stall occurred made a successful recovery impossible.
- The stabilizer trim was set near the full nose-up position, which would have caused a nose-up tendency during takeoff.
- The pilot had limited recent flying experience, having flown only 10 hours in the preceding year, which may have hindered the ability to recognize and recover from the stall.
- The aircraft was not equipped with a stall warning device.
- The aircraft was being operated with automotive gasoline without evidence of required regulatory compliance.